1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/zio.h> 28 29 /* 30 * SHA-256 checksum, as specified in FIPS 180-3, available at: 31 * http://csrc.nist.gov/publications/PubsFIPS.html 32 * 33 * This is a very compact implementation of SHA-256. 34 * It is designed to be simple and portable, not to be fast. 35 */ 36 37 /* 38 * The literal definitions of Ch() and Maj() according to FIPS 180-3 are: 39 * 40 * Ch(x, y, z) (x & y) ^ (~x & z) 41 * Maj(x, y, z) (x & y) ^ (x & z) ^ (y & z) 42 * 43 * We use equivalent logical reductions here that require one less op. 44 */ 45 #define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) 46 #define Maj(x, y, z) (((x) & (y)) ^ ((z) & ((x) ^ (y)))) 47 #define Rot32(x, s) (((x) >> s) | ((x) << (32 - s))) 48 #define SIGMA0(x) (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22)) 49 #define SIGMA1(x) (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25)) 50 #define sigma0(x) (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3)) 51 #define sigma1(x) (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10)) 52 53 static const uint32_t SHA256_K[64] = { 54 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 55 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 56 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 57 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 58 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 59 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 60 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 61 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 62 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 63 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 64 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 65 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 66 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 67 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 68 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 69 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 70 }; 71 72 static void 73 SHA256Transform(uint32_t *H, const uint8_t *cp) 74 { 75 uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64]; 76 77 for (t = 0; t < 16; t++, cp += 4) 78 W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3]; 79 80 for (t = 16; t < 64; t++) 81 W[t] = sigma1(W[t - 2]) + W[t - 7] + 82 sigma0(W[t - 15]) + W[t - 16]; 83 84 a = H[0]; b = H[1]; c = H[2]; d = H[3]; 85 e = H[4]; f = H[5]; g = H[6]; h = H[7]; 86 87 for (t = 0; t < 64; t++) { 88 T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t]; 89 T2 = SIGMA0(a) + Maj(a, b, c); 90 h = g; g = f; f = e; e = d + T1; 91 d = c; c = b; b = a; a = T1 + T2; 92 } 93 94 H[0] += a; H[1] += b; H[2] += c; H[3] += d; 95 H[4] += e; H[5] += f; H[6] += g; H[7] += h; 96 } 97 98 void 99 zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp) 100 { 101 uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 102 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 }; 103 uint8_t pad[128]; 104 int i, padsize; 105 106 for (i = 0; i < (size & ~63ULL); i += 64) 107 SHA256Transform(H, (uint8_t *)buf + i); 108 109 for (padsize = 0; i < size; i++) 110 pad[padsize++] = *((uint8_t *)buf + i); 111 112 for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++) 113 pad[padsize] = 0; 114 115 for (i = 56; i >= 0; i -= 8) 116 pad[padsize++] = (size << 3) >> i; 117 118 for (i = 0; i < padsize; i += 64) 119 SHA256Transform(H, pad + i); 120 121 ZIO_SET_CHECKSUM(zcp, 122 (uint64_t)H[0] << 32 | H[1], 123 (uint64_t)H[2] << 32 | H[3], 124 (uint64_t)H[4] << 32 | H[5], 125 (uint64_t)H[6] << 32 | H[7]); 126 } 127